Plural component spray gun for fast setting materials

ABSTRACT

A plural component spray gun ( 1 ) is designed for spraying quick setting materials such as foams, polyurea and the like. Towards this end, the gun ( 1 ) is designed so as to be easily serviceable with a minimum of tools. For example, the side seal cartridges ( 18 ) and ( 20 ) may be installed and removed without tools by removing the retaining ring ( 9 ) and then extracting them from the fluid housing ( 11 ). Those cartridges ( 18 ) and ( 20 ) are easily disassembled and cleaned. Similarly, the fluid housing ( 11 ) may be removed from the handle/body ( 1 ) by unscrewing the lock ring ( 7 ) by hand.

TECHNICAL FIELD

This application claims the benefit of U.S. application Ser. Nos.60/420,085, filed Oct. 22, 2002, 60/441,575 filed Jan. 21, 2003 and60/462,124 filed Apr. 10, 2003.More than one reissue application hasbeen filed for the reissue of U.S. Pat. No. 7,694,893. This applicationand application Ser. No. 14/662,846 are reissue divisional applicationsof application Ser. No. 13/446,222, which is an application for reissueof U.S. Pat. No. 7,694,893. Application Ser. No. 13/446,222 has beenreissued as U.S. Pat. No. Re. 46,002. This application claims thebenefit of U.S. application Ser. Nos. 60/420,085, filed Oct. 22, 2002,60/441,575 filed Jan. 21, 2003 and 60/462,124 filed Apr. 10, 2003.

BACKGROUND ART

Plural component spray guns for use with fast setting materials havebeen popular for applying foams and similar materials. While suchapplication devices are generally effective in applying such materials,they are often cumbersome and can require a number of tools andsubstantial effort to disassemble and clean.

DISCLOSURE OF THE INVENTION

A plural component spray gun is designed for spraying quick settingmaterials such as foams and the like. Towards this end, the air purgeversion of the gun is designed so as to be easily serviceable with aminimum of tools. For example, the side seal cartridges may be installedand removed without tools by removing the retaining ring and thenextracting them from the fluid housing using a coin or screwdriver. Thecartridges are easily disassembled and cleaned.

Similarly, the fluid housing may be removed from the handle byunscrewing the lock ring (by hand). Grease may be directly injected intothe gun for storage without disassembly and is spread though the mixchamber by the purge air. The mixing chamber and piston are easilyseparated using an ⅛ turn connection. Line of sight air passages in thebody are easy to machine and allow easier service in the field ifplugged.

Impingement hole cleaning may be accomplished without exposing the fluidto air. The sealing surfaces of the side seal cartridge assemblies andthe corresponding surfaces of the mix chamber are made of a hardenedmetal material such 440C stainless steel providing a metal-to-metal sealyielding excellent durability.

In a mechanical purge version of the gun, The air cap is provided with apair of horns spaced so as to correspond with the dimension of the flatson the impingement chamber retainer to allow the retainer to be removedand installed without the use of a separate tool.

Typical prior art mechanical purge guns have two sets of fluid seals toseal the valving rod. The main seal, usually an interference fit, isDelrin A-F and is not adjustable. The front seal is also an interferencefit and made from UHMWPE and also not adjustable. When the main sealwears the gun will “spit” fluid out the front of the gun, plugging thetip. The seals typically wear at similar rates, so when the gun spits,the users replaces both seals.

The impingement chamber forms first and second spaced annular chambersabout the periphery thereof and first and second sets of passagesconnect said chambers with the interior passage thereof. The first andsecond sets of passages enter the interior passage at the same axiallocation thereby preventing a lead-lag situation which can produceunmixed material.

An easily adjustment mechanism for the purge rod is provided. The simpleadjustment may be accomplished by turning the purge rod at the rear ofthe gun using a nut driver or similar tool. The purge rod is threadedlyengaged in the piston while the piston is prevented from rotatingrelative to the gun body by means of complementary flats in the bore andon the piston.

These and other objects and advantages of the invention will appear morefully from the following description made in conjunction with theaccompanying drawings wherein like reference characters refer to thesame or similar parts throughout the several views.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of air purge embodiment of the instantinvention.

FIG. 2 is a partially cutaway view of the instant invention from thesame angle as FIG. 1.

FIG. 3 shows a partially exploded view of the front of the instantinvention.

FIG. 4 shows an exploded view of the side seal cartridge of the instantinvention.

FIG. 5 shows assembly of the mix chamber to the fluid housing.

FIG. 6 shows removal of the fluid housing from the gun body.

FIG. 7 shows an exploded view of the instant invention.

FIG. 8 shows a cross section of a mechanical purge embodiment of theinstant invention.

FIG. 9 shows a front perspective view of the mechanical purge embodimentof FIG. 8 showing the air cap reversed for impingement chamber retainerremoval.

FIG. 10 is a front view of the impingement chamber of the mechanicalpurge embodiment of FIG. 8.

FIG. 11 is a section view taken along line 11-11 of FIG. 10.

FIG. 12 is a section view taken along line 12-12 of FIG. 10.

FIG. 13 is a partially exploded perspective view of the packingarrangement.

FIG. 14 is a partially exploded side view of the packing arrangement.

FIG. 15 is a partially exploded perspective view of the safetyarrangement.

FIG. 16 is a partially exploded side view of the safety arrangement.

FIG. 17 is a partially cutaway view of the mechanical purge embodimentof FIG. 8.

BEST MODE FOR CARRYING OUT THE INVENTION

The air purge spray gun of the instant invention, generally designated100, is shown in whole in FIGS. 1, 2 and 7. Gun 100 is comprised of agun body 1. As can be seen in FIG. 2, air passages 1a are allmanufactured in the line of sight for ease of machining and maintenance.When the piston 15 is removed, the whole length of each of the passagesmay be viewed and easily cleaned using a drill bit.

A releasable piston stop 28 is provided and may be actuated (via a pushand turn) using safety lock 4. O-ring 24 and spring 30 are locatedtherebetween. A rear cylinder cap 5 threads onto the rear of gun body 1and is sealed by o-ring 14. One piece piston 15 slides on the interior1c of gun body 1 (which have complementary flats 15a and 1b to preventrelative rotation) and has a projecting shaft 15a Sealing o-rings 16 and17 are provided.

Mixing chamber 19 has two impingement holes 19a located diametricallyopposite one another. Mixing chamber 19 also has two flattened sides 19bwhich maintain the angular orientation relative to the fluid housing 11.Mixing chamber 19 also has a connecting flange 19c at the rear endthereof for ⅛ turn push and turn engagement (similar to a bayonet joint)with piston projecting shaft 15a. Side seal cartridge assemblies 18 and20 are engaged and retained in fluid housing 11 by a combination of thefriction fit of o-rings 19d and 20d and radial retention by retainingring 9.

Retaining ring 9 also retains air cap 10 which screws to the front ofmix chamber 19. Lock ring 7 is retained to the rear end of fluid housing11 by ring 27. Sealing is provided by seals 10a, 23 and 21. This fluidchamber attachment arrangement allows the fluid section to be removedfrom the body without exposing either of the resin or iso (isocyanate)fluids to atmosphere which would lead to crystallization of the iso.

Side seal cartridge assemblies 18 and 20 are comprised of cartridgehousings 18a and 20a, springs 18b and 20b, seals 18c and 20c and o-rings18d, 20d, 18e and 20e. The sealing surfaces of side seal cartridgeassemblies 18 and 20 (e.g. seal surface 20f) and the correspondingsurfaces 19b of mix chamber 19 are made of a hardened metal materialsuch 440C stainless steel.

Fluid manifold assembly 12 is comprised of a manifold housing 12a, firstand second fluid valves 12b, plugs 12c, bolt 12d and swivels 12e and12f. First and second fluid valves 12b each are provided with a onepiece stem 12h having a hex head with a seal 12i threaded onto the otherend for releasably shutting off fluid flow of the material beingcontrolled. Fluid manifold 12 attaches to fluid housing 11 via bolt 12dand sealing o-ring 12g.

Located on the two sides of fluid housing 11 are check valves 26, eachcheck valve 26 being comprised of a housing 26a, a screw 26b, a carbideball 26c, a screen 26d, a spring 26e and o-rings 26f and 26g. Note thatfluid flows from the inside out through the screen so that fluidpressure cannot collapse the screen 26d as happens on prior art guns.

Trigger 13 is mounted to body 1 by pin 6 and screw 29. The rear oftrigger 13 selectively (by operator operation) contacts spool type airvalve 32 in body 1. Spool type air valve 32 is mounted with 3 o-rings24, spring 31 and air valve plug 2 which is in turn backed by an airquick disconnect 35. O-rings 24 like all o-rings in the gun aresolvent-resistant so that the whole gun (not just the fluid section) canbe soaked in solvent for cleaning. A muffler 22 and plug 33 are alsoprovided in the bottom of gun body 1. Air valve disconnect 35 and plug33 may be exchanged in order to have air come in from the back or bottomas desired by the operator.

A grease zerk fitting 25 is supplied in the fluid housing and connectsto the purge air passage 8a, which is fluidly coupled to purge airpassage 8b in gun body 1. This allows the fluid passages in the mixchamber 19 and the front end of the gun to be filled with grease (whichmixes with the purge air to prevent setup and crystallization. Suchinjection will allow the spray gun to be stored overnight with having tobe completely cleaned. Similarly, the air cap 10 serves to directcleanoff air around the front of the tip 19a 19d so as to preventbuildup thereon.

In a mechanical purge version of the gun 40, The air cap 110 is providedwith a pair of horns 110A spaced so as to correspond with the dimensionof the flats 142A on the impingement chamber retainer 142 to allow theretainer 142 to be removed and installed without the use of a separatetool.

The impingement chamber 144 forms first and second spaced annularchambers 146A and 146B about the periphery thereof and first and secondsets of passages 144A and 144B respectively connect said annularchambers 146A and 146B with the interior passage 144C thereof. The firstand second sets of passages 144A and 144B enter the interior passage144C at the same axial location thereby preventing a lead-lag situationwhich can produce unmixed material. As can be seen, set 144A is axiallyangled and set 144B radial and normal to the axis to achieve thisresult.

An easily adjustment mechanism for the purge rod 148 is provided. Thesimple adjustment may be accomplished by turning the rear end 148A purgerod at the rear of the gun using a nut driver or similar tool. The onepiece purge rod 148 is threadedly engaged in the piston 115 while thepiston is 115 prevented from rotating relative to the gun body 101 bymeans of complementary flats in the bore and on the piston (101A and115A respectively).

The adjustable packing 154 of the instant invention, held in place bythe tip retainer 150 (which also retains tip 152), allows the user tosnug-up the front seal to stop the spitting. This adjustability willallow users to at least finish out the day without changing the mainpacking.

Mechanical Purge gun operators often must actuate the gun safety, whenadjusting air flow or changing tips. The safety 158 must operate easilyunder all conditions. The guns are often covered with overspray fromfoam or polyurea, making safety actuation difficult. The safety sleeve156, made of polyethylene, ensures the safety 158 will be free movingeven when covered in overspray and is shown in FIGS. 15 and 16. Foam orpolyurea will not stick to polyethylene. If there is a build-up on thesafety actuator 160, the polyethylene will shed the over-spray when thesafety 158 is actuated.

It is contemplated that various changes and modifications may be made tothe spray gun without departing from the spirit and scope of theinvention as defined by the following claims.

The invention claimed is:
 1. A spray gun for fast setting pluralcomponent materials, said spray gun comprising: a gun body; an air cap;a retaining ring; a fluid housing removably attached to said gun body,said fluid housing having a threaded surface for threadedly receivingsaid retaining ring and generally opposed first and second radial portsin said threaded surface; and first and second seal cartridges retainedin said ports by friction and said retaining ring.
 2. The spray gun ofclaim 1 wherein said air valve engages said gun body with no more thanthree seals.
 3. The spray gun of claim 1 wherein said air valve isconnected to a muffler in said gun body.
 4. The spray gun of claim 1further comprising a fluid manifold removably fastened to said fluidhousing, said fluid manifold being sealed thereto by an o-ring.
 5. Thespray gun of claim 1 further comprising a fluid manifold, said fluidmanifold comprising a body and first and second fluid valves forconnection to first and second components of a plural componentmaterial, each of said first and second valves comprising a one piecestem having a head thereon to allow manipulation to open or closedpositions; and a seal for sealingly engaging said manifold body.
 6. Thespray gun of claim 1 further comprising: a mix chamber located in saidfluid housing; a purge air passage located in said fluid housing; a zerkfitting in said fluid housing and connected to said purge air passagefor receiving protective material.
 7. The spray gun for fast settingplural component materials of claim 1 further comprising a fluid housinghaving a mix chamber located therein and said first and second sealcartridges sealing against said mix chamber, said cartridges and saidmix chamber comprising sealing surfaces comprised of a hardenedmaterial.
 8. The spray gun for fast setting plural component materialsof claim 7 wherein said mix chamber is formed from a hardened material.9. The spray gun for fast setting plural component materials of claim 8wherein said hardened material is 440C stainless steel.
 10. The spraygun for fast setting plural component materials of claim 1 furthercomprising a grease fitting in said fluid housing for injection ofgrease into said spray gun for storage.
 11. A spray gun for fast settingplural component materials, said spray gun comprising: a gun body; anair cap; a fluid housing attached to said gun housing and receiving saidair cap and generally a mix chamber located in said fluid housing; apurge air passage located in said fluid housing; and a zerk fitting insaid fluid housing and connected to said purge air passage for receivingprotective material.
 12. A spray gun for fast setting plural componentmaterials, said spray gun comprising: a gun body; an air cap; and afluid housing attached to said gun body, said fluid housing comprising:a mix chamber located in said fluid housing; a purge air passageextending through said fluid housing from said gun body; a fittingconnected to said purge air passage for receiving protective material;and first and second seal cartridges retained in said fluid housing;wherein said fluid housing receives said air cap and wherein said firstand second seal cartridges and said mix chamber comprise sealingsurfaces comprised of a hardened material.
 13. The spray gun for fastsetting plural component materials of claim 31 wherein: the fittingconnected to said purge air passage for receiving protective materialcomprises a zerk fitting located in said fluid housing.
 14. The spraygun for fast setting plural component materials of claim 31 furthercomprising: a fastener for retaining said first and second sealcartridges in the fluid housing.
 15. The spray gun for fast settingplural component materials of claim 34 wherein: the fastener comprises aretaining ring.
 16. The spray gun for fast setting plural componentmaterials of claim 31 wherein the first and second seal cartridges eachcomprise: a cartridge housing having one or more solvent resistanto-rings located on an outer surface; a seal having a cartridge sealsurface and being located within the cartridge housing so that a springbiases the cartridge seal surface against the mix chamber; and a springdisposed between the cartridge housing and the seal.
 17. A spray gun forfast setting plural component materials, said spray gun comprising: agun body; a piston located within the gun body configured to receive aconnecting flange of a mix chamber and movable between a first positionand a second position; an air cap; and a fluid housing attached to saidgun body, said fluid housing comprising: a mix chamber located in saidfluid housing and connected to the piston by a connecting flange so thatmovement of the piston causes movement of the mix chamber; a purge airpassage extending through said fluid housing from said gun body; andfirst and second seal cartridges retained in said fluid housing; whereinsaid first and second seal cartridges and said mix chamber comprisesealing surfaces comprised of a hardened material.
 18. The spray gun forfast setting plural component materials of claim 17 further comprising:an air valve located within the gun body and connected to a trigger; anda trigger located outside the gun body and connected to the air valve;wherein depressing the trigger moves the air valve so that the pistonmoves from the first position to the second position causing material tobe dispensed.
 19. The spray gun for fast setting plural componentmaterials of claim 18 further comprising: a piston stop located betweenthe piston and an end of the gun body for preventing movement of thepiston; and a safety lock located outside the gun body and connected tothe piston stop for engaging and disengaging the piston stop; whereinwhen the piston stop is engaged the piston stop prevents the piston frommoving when the trigger is depressed.
 20. The spray gun for fast settingplural component materials of claim 18 further comprising: a mufflerattached to the gun body for reducing noise.
 21. The spray gun for fastsetting plural component materials of claim 17 further comprising: afitting connected to said purge air passage for receiving protectivematerial.
 22. The spray gun for fast setting plural component materialsof claim 21 wherein: the fitting connected to said purge air passagecomprises a zerk fitting.
 23. The spray gun for fast setting pluralcomponent materials of claim 17 further comprising: a fastener forretaining said first and second seal cartridges in the fluid housing.24. The spray gun for fast setting plural component materials of claim23 wherein: the fastener comprises a retaining ring.
 25. A spray gun forfast setting plural component materials, said spray gun comprising: agun body; an air cap; a fluid housing attached to said gun body, saidfluid housing having: generally opposed first and second radial ports;and a mix chamber located therein and comprising an elongate body havingfirst and second flattened sides comprising mix chamber seal surfaces;and first and second seal cartridges retained in said first and secondradial ports and sealing against the flattened sides of said mixchamber; wherein said first and second seal cartridges and said mixchamber seal surfaces are comprised of a hardened material.
 26. Thespray gun for fast setting plural component materials of claim 25further comprising a fluid manifold removably fastened to said fluidhousing, said fluid manifold being sealed thereto by an o-ring.
 27. Thespray gun for fast setting plural component materials of claim 25further comprising: a fastener for retaining said cartridges to thefluid housing.
 28. The spray gun for fast setting plural componentmaterials of claim 25 further comprising a retaining ring that engages athreaded surface of the fluid housing and is configured to be removableby hand.
 29. The spray gun for fast setting plural component materialsof claim 25 wherein: said first and second seal cartridges eachcomprise: a cartridge housing mounted to one of the radial ports; a sealhaving a cartridge seal surface and being located within the cartridgehousing so that a spring biases the cartridge seal surface against oneof the first and second flattened sides; and a spring disposed betweenthe cartridge housing and the seal.
 30. The spray gun for fast settingplural component materials of claim 29 further comprising: a purge airpassage located in said fluid housing and intersecting the mix chamber.31. The spray gun for fast setting plural component materials of claim30 further comprising: a grease fitting coupled to said purge airpassage.
 32. The spray gun for fast setting plural component materialsof claim 25 wherein the hardened material comprises 440C stainlesssteel.
 33. A spray gun for fast setting plural component materials, saidspray gun comprising: a gun body; an air cap; a fluid housing attachedto said gun body, said fluid housing comprising: generally opposed firstand second radial ports; a mix chamber located therein; and one or morecheck valves; a lock ring for attaching said fluid housing to said gunbody wherein said lock ring is configured to be loosened by hand toallow removal of the fluid housing from the gun body; first and secondseal cartridges configured to be removed by hand retained in said radialports and sealing against said mix chamber; and a retaining ring forretaining said first and second seal cartridges in said radial portsthat engages a threaded surface of the fluid housing and is configuredto be removable by hand.
 34. The spray gun for fast setting pluralcomponent materials of claim 33, further comprising: a fluid manifoldassembly comprising: first and second fluid valves; and a one piece stemhaving a hex head with a seal for shutting off fluid flow; wherein thefluid manifold assembly is removably attached to the fluid housing frombelow using a bolt and sealing o-ring; and wherein the first and secondfluid valves of the fluid manifold assembly are capable of fluidcommunication with the first and second seal cartridges.
 35. The spraygun for fast setting plural component materials of claim 33 wherein themix chamber further comprises first and second flattened sides andwherein said first and second seal cartridges each comprise: a cartridgehousing mounted to one of the radial ports; a seal having a cartridgeseal surface and being located within the cartridge housing so that aspring biases the cartridge seal surface against one of the first andsecond flattened sides; and a spring disposed between the cartridgehousing and the seal.
 36. The spray gun for fast setting pluralcomponent materials of claim 35 further comprising: a purge air passagelocated in said fluid housing and intersecting the mix chamber.
 37. Thespray gun for fast setting plural component materials of claim 36further comprising: a grease fitting coupled to said purge air passage.38. A spray gun for fast setting plural component materials, said spraygun comprising: a gun body; an air cap; a fluid housing attached to saidgun body, said fluid housing having: generally opposed first and secondradial ports; and a mix chamber located therein and comprising anelongate body having first and second flattened sides comprising mixchamber seal surfaces; a lock ring for attaching said fluid housing tosaid gun body wherein said lock ring is configured to be loosened byhand to allow removal of the fluid housing from the gun body; first andsecond seal cartridges configured to be removed by hand retained in saidfirst and second radial ports and sealing against said flattened sidesof said mix chamber; and a retaining ring for retaining said first andsecond seal cartridges in said first and second radial ports thatengages a threaded surface of the fluid housing and is configured to beremovable by hand; wherein said first and second seal cartridges andsaid mix chamber seal surfaces are comprised of a hardened material. 39.The spray gun for fast setting plural component materials of claim 38wherein said first and second seal cartridges each comprise: a cartridgehousing mounted to one of the first and second radial ports; a sealhaving a cartridge seal surface and being located within the cartridgehousing so that a spring biases the cartridge seal surface against oneof the first and second flattened sides; and a spring disposed betweenthe cartridge housing and the seal.
 40. The spray gun for fast settingplural component materials of claim 39 further comprising: a purge airpassage located in said fluid housing and intersecting the mix chamber.41. The spray gun for fast setting plural component materials of claim40 further comprising: a grease fitting coupled to said purge airpassage.
 42. The spray gun for fast setting plural component materialsof claim 38 wherein the hardened materials comprise 440C stainlesssteel.